Method of rolling hollow rounds



I 1,624,340 Aprll 12, 1927. A. w HEINLE METHOD ROLLING HOLLOW ROUNDS Filed Feb. 19, 1925 3 Sheets-Sheet l W7 INVENTOR wrrN E sax-2s 1 7 WWW (I l v r M Maw y 44a 0 1,624,340 April 12, 9 w. HEINLE METHOD OF ROLLING HOLLOW ROUNDS Filed Feb. 19. 1926 3 Sheets-Sheet 2 ""1 f 'l fi J I a u q INVENTOR mil M Ala W 1,624,340 Aprll 12, 1927. A. W HEINLE METHOD OF ROLLING HOLLOW ROUNDS Filed F'eb 19. 1925 3 Sheets-Sheet 3 WITNESSES INVENTOR Patented Apr. 12, H527;

UNITED STATES. PATENT OFFICE.

I ALBERT W. HEINLE, OF GRAFTON, PENNSYLVANIA, ASSIGNOR OE ONE-HALF TO HENRY F. GILG, OI PITTSBURGH, PENNSYLVANIA.

METHOD OF ROLLING HOLLOW ROUNDS.

Application filed February 19, 1928. Serial No. 89,841.

My invention relates to a method of rolling unjoined tubular sections from solid bars. or billets of ferrous and non-ferrous metals, and more particularly to the forming of tubular sections having relatively thick wall portions.

It is among the objects of my invention to provide a method of forming unjoin'ed tubular sections from solid bars or billets which comprises forming or shaping the billet by progressive conformations to produce a geometrical design of the dimensions corresponding to the circumferential ratio of the tubular section to be formed.

Another object oi my invention is to form unjoined tubular sections having relativel thick walls, bya series of successive rol passes to produce a bar of suitable shape and' dimensions by progressive conformation, and subsequently reforming the bar so formed to produce an unjoined circular section. n

Another object of my invention is to form unjoined tubular sections from solid bars or billets, the abutting bar edges of which shall be of an area corres onding to that of its wall section, and which in its final pass shall form a tightly abutting joint.

Another object of my invention is to form unjoined tubular sections by a series of roll passes from a solid bar or billet by reducing and progressively conforming the billet to a L geometrical design with similarity of shape for each successive conformation, thereby as preventing the setting up of transverse and longitudinal stressesin the structure of the metal throughout the entire roll pass operation'.

Various methods for the making of thick 40 walled tubular sections have been heretofore proposed, one of which comprises rolling a metal billet to the shape of a U-section and by a subsequent'series of roll passes to a section of substantially circular shape, for 4 example, as is described in U. S, Patent No. 315,626. Other processes for forming tubes which have been practiced more recently comprise the joining. of a number of crescent shape sections by roll-passing them at a welding heat, the sections having previously been formed by rolling on pressing sheets or bars.

rolling hollow billets having a sand core to a ,a circular section.

Numerous difiiculties have been encoun- Still another process comprises.

tered in the making of thick walled circular sections by the aforementioned methods leading to an inferior product of var ing quality. In the forming of rounds rom U sections by a rolling rocess' the lower portion of the round is ormed in the initial passes and the structure of the metal of this round portion remains positive or fixed during the forming of the upper ends of the U into a round section. During the final passes of the operation the metal is drawn and the grain structure is opened instead of closed, and furthermore, the bar edges of the unjoined circular section form a -shaped opening or gap which in some instances is closed by the deposition of metal as by arc welding and subsequently subjected to a final roll pass which, however,

does not cure the irregularity of the metal structure produced by the weld. For these 76 reasons the making of tubular sections from U-shape sections must be confined to the forming of tubes of relatively thin wall sections.

Tubing made by the joining of crescent shape sections is subject to the criticism that the resulting tube structure is of nonuniform strength and of irregular texture on account of the seams or joints formed at the juncture of the sections from which 35 the tube'is made.

The objection of the employment of hollow sand-filled billets for the manufacture of thick walled tubular sections is the expense of making the hollow billets and this process by its nature of working the metal 18 confined to granular metals instead of those of fibrous structure such as wrought.

My present invention) obviates the difiiculties encountered in these prior art methods of forming thick walled tubular sections, and is particularly adapted to the. making of hollow round billets that may be subsequently further reduced or worked upon to make them suitable for the manufac-' ture of hollow sta bolts for steam locomotives and for ho ow axles, shafting and other a plications where tubular sections of relative y thick wall portions are required. In carryingout my invention I employ three-hi h coactin rolls of two sections, in one section of which the rolls are provided with grooves and tongues of complementary shape for progressively conforming a billet Fig. 3 to the shapes 3, 4

- and or bar to a winged section, the upper and bottom contour of which substantially corresponds in dimensions to the circumferential dimensions of an'unjoined tubular section. The rolls of theother section being provided with rooves and coacting tongues for reforming the winged bar to an oval shaped leader for the final pass to form the round or circular section.

During the passing of the billet through the first-mentioned section of rolls the resulting shape embodies the required contour of the bar ed es and also the dimensions that represent t 1e inner and outer circumferences of a thick wall circular section. The subsequent passing through the other roll section reforms the bar to its final shape.

In the accompanying drawings constituting a part hereof, and in which like reference characters designate like parts, Figs. 1 and 2 are views of a roll-passed bar showing the geometrical design and the similarity in dimensions maintained during the reduction, conforming and subsequent reforming of the billet to form an unjoined circular section in accordance with the principles of my invention; Fig. 3 is a side elevational view of one section of the rolls, having the bars shown in hatched sections, for ro ressivel reducing and conforming tlie ar; ig. 4 is asimilar view of the section of the roll for reforming the bar to an unjoined circular section.

Referring to Figs. 3 and 4 of the drawings, the structure therein illustrated com: prises three-high rolls in which the upper and lower rolls A and B are provided with coves a and collars b, and the center rolls with complementary shaped tongues 0 coactin with the grooves.

Re errin to Figs. 1 and 2 of the drawings, a billet 1 o rectangular shape is inserted in the first pass of Fig. 3 conformin itto the sha 2 and it is subsequently red con ormed through the successive passes of 5, 6 and 7. In the initial roll-pass the billet assumes a geometrical design that easily and practice 1y negotiates all successive progressive passes without setting 11 dinal stresses in t e structure of the metal while being reduced, conformed and solidified, thus leaving the metal in such physical condition that it may be safely and readily reformed to the shapes 8, 9, l0 and 11, Fig. 2, by the passes of the rolls of Fig. a. n

the progressive conformation of the metal by rolling, as illustrated in Figs. 2 to 7, inclusive, the co-related lengths or dimensions of the inner and outer circumferences 12 and 13 of the unjoined circular section 11 is developed and the bar edges 14 that constitute the 'oint 15 in the circular section 11 are forms simultaneously with the upper and lower contours 16 and, 17 corresponduced and transverse and longituing to the circumferences of the section 11. The confronting faces of the bar edges 14- are of complementary shape and of a transverse area at least equal to the area of the normal wall section of the tubular section 11.

The section 7 of Fig. 1 is of maximum cross-section through its central portion to provide suflicient metal to change the Wing shape 7 in the reformin passes to the shapes 8 and 9. As shown in Ihgs. 1 and2, the angle 1 of the abutting bar edges 14 and the inner circumference is maintained for the sections 7 to 10, inclusive, and in the reforming of the oval shape of section 10 from section 9 the inner dimension of the bar closes, leaving a wedge-shaped spacebetween the bar edges 14. In the subsequent final pass both the outer and inner circumferences of the bar are changed from an oval to a circular shape thereby completely closing the gap between the bar edges 14. In the final pass the oval shape is disposed in the manner shown in dotted lines in Fig. 4: withthe abutting bar edges in a vertical position or transversely to the roll axis.

Referring to the wing section 7 and the unjoined circular section 11, Fi s. 1 and 2, thesesections are substantially identical in their surface contour. The form of section 7 is obtained from section 11, by opening the latter to a fiat section in the successive steps of the shapes of sections 10, 9, 8 and 7. This is illustrated by the shape of the passes in the reforming rolls Fig. 4, in which ressure is exerted on the center portion 0 the section 7 to effect a natural bendin of the bar to form it to the section 8 an in the next pass to the section 9. The subsequent passes close and reform the oval section to the round. but the contour and the circumferential dimensions of sections 7 to 11 inclusive are substantially maintained throughout the reforming asses. It is further to' be noted that the s ape of the end portions of section 7, extending from the dotted lines, is not changed in the reforming passes and that the angle 4: is unchan' ed in these passes.

Although I have descri ed a specific embodiment of my invention, it will be obvious to those skilled in the art that modifications may be made in the shape, design and types of rolls employed in working the metal, without departing from the principles herein set forth.

, I claim:

1. The Inethodof forming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a. series of rolls successively changing the shape of said billet by diiferent operations to develop the co-related lengthsor dimensions of the inner and outer circumferences of an unjoined circular section.

2: The method of forming blanks for use which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to develop the co-related lengths or dimens'ons of the inner and outer circumferences 0 an unjoined circular section, the wall of saidcircular section being of a substantially smaller dimension than the thickness of the billet.

. 3. The method of forming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to develop the co-related lengths or dimensions of the inner and outer circumferences of an unjoined circular section, the confronting faces of which are of complementary shape.

4. The method of forming blanks for use in the manufacture of thick Walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to develop the co-related lengths or dimensions of the inner and outer circumferences of an unjoined circular section with contiguous bar edges, the confronting edge faces of which are of complementary shape.

,5. The method of forming blanks for use -in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to develop the co-related lengths or dimensions of the inner and'oute'r circumferences of an unjoined circular section with bar edges, the confronting faces of which are of complementary shape, and of a transverse area substantially equal to that of the normal wall section.

6. The method of forming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to develop its top and bot- 8. The method of forming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to develop a geometrical design in an initial pass which is maintained in the succeeding passes, and subsequently reforming the rolled metal to an unjoined circular section.

9. The method of forming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to develop a geometrical; design that prevents setting up transverse and longitudinal stresses in the structure'of the metal during the rolling operation, and subsequently reforming the metal to an unjoined circular section.

10. The method offorming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by diiferent operations to a section of substantially uniform thickness. throughout having its side portions of substantially the configuration of portions of a cylindrical tube and having the upper and lower transverse lengths of its surfaces substantially the same as the inner and outer circumference of the tube whereby the edges of the blank meet in a plane when the blank is shaped to cylindrical form.

11. The method of forming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to the co-related lengths or dimensions of the inner and outer circumferences of an unjoined circular section and subsequently forming, by a natural bending of the section so formed, a circular section of corresponding dimensions.

12. The method of forming blanks for use in the manufacture of thick walled tubing which comprises passing a blank in billet form through a series of rolls successively changing the shape of said billet by different operations to one of substantially uniform thickness having convex middle sections and reversibly curved ends, through further passes, bendin said ends towards each other and finally finishing the blank to circular form-with ends parallel in substantial contact and extending radially of the blank. I

In testimony whereof, I sign my name.

' ALBERT W. HEINLE. 

